From 9013415593868b2d31a895e3f1f209fc21b58384 Mon Sep 17 00:00:00 2001 From: Richard Mudgett Date: Thu, 2 Nov 2017 18:40:20 -0500 Subject: [PATCH] Fix ast_(v)asprintf() malloc failure usage conditions. When (v)asprintf() fails, the state of the allocated buffer is undefined. The library had better not leave an allocated buffer as a result or no one will know to free it. The most likely way it can return failure is for an allocation failure. If the printf conversion fails then you actually have a threading problem which is much worse because another thread modified the parameter values. * Made __ast_asprintf()/__ast_vasprintf() set the returned buffer to NULL on failure. That is much more useful than either an uninitialized pointer or a pointer that has already been freed. Many uses won't have to check for failure to ensure that the buffer won't be double freed or prevent an attempt to free an uninitialized pointer. * stasis.c: Fixed memory leak in multi_object_blob_to_ami() allocated by ast_asprintf(). * ari/resource_bridges.c:ari_bridges_play_helper(): Remove assignment to the wrong thing which is now not needed even if assigning to the right thing. Change-Id: Ib5252fb8850ecf0f78ed0ee2ca0796bda7e91c23 --- apps/app_mixmonitor.c | 2 ++ include/asterisk/utils.h | 8 +++++++- main/db.c | 8 +++++--- main/json.c | 2 +- main/stasis.c | 7 ++++--- main/utils.c | 8 +++++++- res/ari/resource_bridges.c | 1 - res/res_xmpp.c | 7 +++++-- 8 files changed, 31 insertions(+), 12 deletions(-) diff --git a/apps/app_mixmonitor.c b/apps/app_mixmonitor.c index b1579a70ac..9f147768dd 100644 --- a/apps/app_mixmonitor.c +++ b/apps/app_mixmonitor.c @@ -818,6 +818,8 @@ static int setup_mixmonitor_ds(struct mixmonitor *mixmonitor, struct ast_channel if (ast_asprintf(datastore_id, "%p", mixmonitor_ds) == -1) { ast_log(LOG_ERROR, "Failed to allocate memory for MixMonitor ID.\n"); + ast_free(mixmonitor_ds); + return -1; } ast_mutex_init(&mixmonitor_ds->lock); diff --git a/include/asterisk/utils.h b/include/asterisk/utils.h index 4a5dbf282c..03705b321a 100644 --- a/include/asterisk/utils.h +++ b/include/asterisk/utils.h @@ -721,7 +721,13 @@ int _ast_vasprintf(char **ret, const char *file, int lineno, const char *func, c DEBUG_CHAOS_RETURN(DEBUG_CHAOS_ALLOC_CHANCE, -1); - if ((res = vasprintf(ret, fmt, ap)) == -1) { + res = vasprintf(ret, fmt, ap); + if (res < 0) { + /* + * *ret is undefined so set to NULL to ensure it is + * initialized to something useful. + */ + *ret = NULL; MALLOC_FAILURE_MSG; } diff --git a/main/db.c b/main/db.c index 4bb9355c66..ab5f7a07c2 100644 --- a/main/db.c +++ b/main/db.c @@ -193,9 +193,11 @@ static int convert_bdb_to_sqlite3(void) char *cmd; int res; - ast_asprintf(&cmd, "%s/astdb2sqlite3 '%s'\n", ast_config_AST_SBIN_DIR, ast_config_AST_DB); - res = ast_safe_system(cmd); - ast_free(cmd); + res = ast_asprintf(&cmd, "%s/astdb2sqlite3 '%s'\n", ast_config_AST_SBIN_DIR, ast_config_AST_DB); + if (0 <= res) { + res = ast_safe_system(cmd); + ast_free(cmd); + } return res; } diff --git a/main/json.c b/main/json.c index f45d585c1f..057a262125 100644 --- a/main/json.c +++ b/main/json.c @@ -462,7 +462,7 @@ struct ast_json *ast_json_vstringf(const char *format, va_list args) if (format) { int err = ast_vasprintf(&str, format, args); - if (err > 0) { + if (err >= 0) { ret = json_string(str); ast_free(str); } diff --git a/main/stasis.c b/main/stasis.c index 48e4eb5a55..2d99805170 100644 --- a/main/stasis.c +++ b/main/stasis.c @@ -1344,7 +1344,7 @@ static struct ast_str *multi_object_blob_to_ami(void *obj) for (type = 0; type < STASIS_UMOS_MAX; ++type) { for (i = 0; i < AST_VECTOR_SIZE(&multi->snapshots[type]); ++i) { - char *name = ""; + char *name = NULL; void *snapshot = AST_VECTOR_GET(&multi->snapshots[type], i); ami_snapshot = NULL; @@ -1354,11 +1354,11 @@ static struct ast_str *multi_object_blob_to_ami(void *obj) switch (type) { case STASIS_UMOS_CHANNEL: - ami_snapshot = ast_manager_build_channel_state_string_prefix(snapshot, name); + ami_snapshot = ast_manager_build_channel_state_string_prefix(snapshot, name ?: ""); break; case STASIS_UMOS_BRIDGE: - ami_snapshot = ast_manager_build_bridge_state_string_prefix(snapshot, name); + ami_snapshot = ast_manager_build_bridge_state_string_prefix(snapshot, name ?: ""); break; case STASIS_UMOS_ENDPOINT: @@ -1369,6 +1369,7 @@ static struct ast_str *multi_object_blob_to_ami(void *obj) ast_str_append(&ami_str, 0, "%s", ast_str_buffer(ami_snapshot)); ast_free(ami_snapshot); } + ast_free(name); } } diff --git a/main/utils.c b/main/utils.c index 0824a373a5..0342030460 100644 --- a/main/utils.c +++ b/main/utils.c @@ -2389,7 +2389,13 @@ int _ast_asprintf(char **ret, const char *file, int lineno, const char *func, co va_list ap; va_start(ap, fmt); - if ((res = vasprintf(ret, fmt, ap)) == -1) { + res = vasprintf(ret, fmt, ap); + if (res < 0) { + /* + * *ret is undefined so set to NULL to ensure it is + * initialized to something useful. + */ + *ret = NULL; MALLOC_FAILURE_MSG; } va_end(ap); diff --git a/res/ari/resource_bridges.c b/res/ari/resource_bridges.c index 8c058c4a7b..d6a0400c86 100644 --- a/res/ari/resource_bridges.c +++ b/res/ari/resource_bridges.c @@ -387,7 +387,6 @@ static int ari_bridges_play_helper(const char *args_media, if (ast_asprintf(playback_url, "/playbacks/%s", stasis_app_playback_get_id(playback)) == -1) { - playback_url = NULL; ast_ari_response_alloc_failed(response); return -1; } diff --git a/res/res_xmpp.c b/res/res_xmpp.c index 6ba4014c70..1b0ae427bc 100644 --- a/res/res_xmpp.c +++ b/res/res_xmpp.c @@ -3911,8 +3911,11 @@ static int fetch_access_token(struct ast_xmpp_client_config *cfg) struct ast_json_error error; RAII_VAR(struct ast_json *, jobj, NULL, ast_json_unref); - ast_asprintf(&cmd, "CURL(%s,client_id=%s&client_secret=%s&refresh_token=%s&grant_type=refresh_token)", - url, cfg->oauth_clientid, cfg->oauth_secret, cfg->refresh_token); + if (ast_asprintf(&cmd, + "CURL(%s,client_id=%s&client_secret=%s&refresh_token=%s&grant_type=refresh_token)", + url, cfg->oauth_clientid, cfg->oauth_secret, cfg->refresh_token) < 0) { + return -1; + } ast_debug(2, "Performing OAuth 2.0 authentication for client '%s' using command: %s\n", cfg->name, cmd);